class UrlMappings {
static mappings = {

        "/$controller/$action?/$id?" {
            constraints {
                // apply constraints here
            }
        }

        "/image/$id/$size?/$filename?" {
            constraints {
                size(matches: /\d+/)
            }
            controller = 'picture'
            action = 'view'
        }

        "500" (view: '/error')

       // "/" (controller: 'listing', action: 'list')

    }
}
